The Eisenberg -- were called before a federal grand jury looking into the case. They wouldn't talk with us about what happened but there is speculation they did not answer questions since they reportedly spent only fifteen minutes inside. There are millions of people out there watching you on this program. For the record I have to ask in front of all of these people. Did you have anything to do with the disappearance of your -- no. Not in any way you know -- Any accident any you know possibly could have happened that you would be afraid to talk about no. And. That's how our original report on the case ended since then mar lean and Steve Eisenberg left Florida and moved to Maryland. But authorities have never given up trying to crack the case for nearly two years they continued their exhaustive investigation. And yesterday a bombshell. Development. In. Federal grand jury here in Tampa. Returned an indictment charging Steven and Marlene -- With serious crimes in connection with bureau reported. Kidnapping of their five month old infant Sabrina. Stephen -- Lee Eisenberg were indicted and arrested by the FBI. The parents who wants pleaded for help in finding their baby -- themselves. Charged in connection with her disappearance. What this indictment alleges that -- the baby was not kidnapped. As reported by the -- -- That they lied to law enforcement authorities concerning the circumstances surrounding the baby's disappearance. And -- reaction to it. As well as the condition of the baby at the time of the reported kidnapping. The indictment also charges the couple used money from a bank account set up to find the child to pay off credit card debts. But the most explosive charges stem from conversations reportedly obtained by -- listening device planted in their Florida home. For instance according to the indictment on December 23 19971. Month after the baby was reported missing. -- is quoted as saying to her husband the baby's dead and buried it was found dead because you did it. The baby's dead no matter what you say you just did it. Steve replies honey there was nothing I could do about it. We need to discuss the way that we can beat the charge we will do what we have to do. Even in light of these new startling revelations the -- in Byrd's attorney Barry Cohen still insists his clients have done nothing wrong. This is a combination a lot of innocent acts. Innocent conduct which has been taken and twisted and manipulated. And try to make it appear the sinister. But authorities suspect there was nothing innocent about apparent injuries to the baby. According to the indictment investigators say the -- and burns became upset when confronted with still pictures taken from their home videotape shot by -- -- just before the baby's disappearance. Authorities say there appear to be injuries to Sabrina -- head -- face in a recorded conversations Steve sent to -- -- I wish I hadn't harmed her and according to federal authorities He continued it was the cocaine. The -- -- burns' attorneys say that too was taken out of context. But given all this apparent new evidence why hasn't the couple been charged with a more serious crime. Eddie Suarez a former state prosecutor in Florida offered a possible explanation. It appears that law enforcement has not develop enough evidence. To seek. An indictment for for murder. It appears it they believe that enough has been developed to show that. The Eisenberg lied. To law enforcement in the course of their investigation and that's a crime both in the state of Florida and under. Federal law tonight the Eisenberg are free on bail and two weeks they were expected to appear before a judge in Tampa. Still the mystery remains unsolved. Where is baby Sabrina. While cost -- -- He will continue to follow developments in this case we will keep you posted.

This transcript has been automatically generated and may not be 100% accurate.

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